Respectful Cameras :

A new type of video surveillance protects the privacy of individuals.

A camera developed by computer scientists at the University of California, Berkeley, would obscure, with an oval, the faces of people who appear on surveillance videos. These so-called respectful cameras, which are still in the research phase, could be used for day-to-day surveillance applications and would allow for the privacy oval to be removed from a given set of footage in the event of an investigation.

"Cameras are here to stay, and there's no avoiding it," says UC Berkeley computer scientist Ken Goldberg. "Let's figure out new technology to make them less invasive." According to a 2006 report prepared by the New York Civil Liberties Union, the number of publicly and privately owned video cameras in Lower Manhattan increased by a factor of five between 1998 and 2005, and several thousand cameras are in place in Greenwich Village and Soho alone. The United Kingdom, however, holds the record for video surveillance. In a report filed on Tuesday, the information commissioner there estimates that there are four million video-surveillance cameras in the United Kingdom--that's one for every 14 people. Goldberg thinks of the respectful cameras as a compromise between advocates for privacy and those concerned about security.

Voyage of the Bacteria Bot :

Self-propelled microbots navigate through blood vessels.

The 1966 science-fiction movie Fantastic Voyagefamously imagined using a tiny ship to combat disease inside the body. With the advent of nanotechnology, researchers are inching closer to creating something almost as fantastic. A microscopic device that could swim through the bloodstream and directly target the site of disease, such as a tumor, could offer radical new treatments. To get to a tumor, however, such a device would have to be small and agile enough to navigate through a labyrinth of tiny blood vessels, some far thinner than a human hair.

Researchers at the École Polytechnique de Montréal, in Canada, led by professor of computer engineeringSylvain Martel, have coupled live, swimming bacteria to microscopic beads to develop a self-propelling device, dubbed a nanobot. While other scientists have previously attached bacteria to microscopic particles to take advantage of their natural propelling motion, Martel's team is the first to show that such hybrids can be steered through the body using magnetic resonance imaging (MRI).

To do this, Martel used bacteria that naturally contain magnetic particles. In nature, these particles help the bacteria navigate toward deeper water, away from oxygen. "Those nanoparticles form a chain a bit like a magnetic compass needle," says Martel. But by changing the surrounding magnetic field using an extended set-up coupled to an MRI machine, Martel and his colleagues were able to make the bacteria propel themselves in any direction they wanted.

The bacteria swim using tiny corkscrewlike tails, or flagella, and these particular bacteria are faster and stronger than most, says Martel. What's more, they are just two microns in diameter--small enough to fit through the smallest blood vessels in the human body. The team treated the polymer beads roughly 150 nanometers in size with antibodies so that the bacteria would attach to them. Ultimately, the researchers plan to modify the beads so that they also carry cancer-killing drugs.

Robo Bird-Watcher :

An intelligent video system in an Arkansas bayou searches for an elusive bird.

Researchers from the University of California, Berkeley and from Texas A&M University have developed a new kind of bird-watching system that automatically identifies birds in flight and records their movements in high-resolution video. Preliminary results and video clips from the ongoing project were presented on Saturday at the annual meeting of the American Association for the Advancement of Science, in San Francisco.

Ultimately, the researchers hope the cameras catch a glimpse of the ivory-billed woodpecker. The search for the woodpecker, long thought to be extinct, was revitalized in 2004 when a bird resembling the species was caught on video in the Cache River National Wildlife Refuge of eastern Arkansas. The video was too blurry, however, to allow a definitive identification. Field biologists sat in canoes for hours, waiting for an ivory-billed woodpecker to fly by so they'd have more-conclusive evidence.

"It's incredibly difficult and tedious," says Ken Goldberg, one of the lead researchers on the project and a professor of engineering at the University of California, Berkeley. "Even if they see something, getting the camera focused [quickly] is very tricky." Some birders were using motion sensors to trigger video cameras, but Goldberg says the equipment wasn't sensitive enough to detect the relatively small creatures.

Intrigued by the problem, Goldberg and colleagueDezhen Song, an assistant professor of computer science at Texas A&M University, designed a special system to aid in the search. Known as theAutomated Collaborative Observatory for Natural Environments(ACONE), the two-camera system scans a patch of sky (measuring roughly 300 feet by 900 feet) above the Cache River refuge. Goldberg says it's an ideal location because it's a high-traffic area for birds and clear of treetops, so the cameras get a relatively unobstructed view. The cameras are mounted on a power-line pole, along with a computer, in the middle of a bayou.

As the cameras scan the sky, each one captures images at 11 frames per second. Those frames are temporarily stored in a buffer. Software on the computer analyzes each frame immediately, looking for things that roughly match the speed and size of an ivory-billed woodpecker. When a bird is detected, Goldberg explains, the system permanently records and stores the previous seven frames and the next seven frames of video on the hard drive. Each frame has a resolution of 1,600 by 1,200 pixels. To save storage space, frames that the software deems irrelevant are automatically deleted.

The software also saves time. The fewer images collected, the fewer canoe trips are required to replace the hard drive in the middle of the bayou. More important, the automatic identification system means that human eyes are spared from watching endless hours of empty sky.